/*
 * jQuery Plugin: Tokenizing Autocomplete Text Entry
 * Version 1.6.0
 *
 * Copyright (c) 2009 James Smith (http://loopj.com)
 * Licensed jointly under the GPL and MIT licenses,
 * choose which one suits your project best!
 *
 */

(function ($) {
  // Default settings
  var DEFAULT_SETTINGS = {
    // Search settings
    method: "GET",
    contentType: "json",
    queryParam: "q",
    searchDelay: 300,
    minChars: 1,
    propertyToSearch: "name",
    jsonContainer: null,

    // Display settings
    hintText: "Type in a search term",
    noResultsText: "No results",
    searchingText: "Searching...",
    deleteText: "&times;",
    animateDropdown: true,

    // Tokenization settings
    tokenLimit: null,
    tokenDelimiter: ",",
    preventDuplicates: false,

    // Output settings
    tokenValue: "id",

    // Prepopulation settings
    prePopulate: null,
    processPrePopulate: false,

    // Manipulation settings
    idPrefix: "token-input-",

    // Formatters
    resultsFormatter: function(item){
      return "<li>" + item[this.propertyToSearch]+ "</li>"
    },
    tokenFormatter: function(item) {
      return "<li><p>" + item[this.propertyToSearch] + "</p></li>"
    },

    // Callbacks
    onResult: null,
    onAdd: null,
    onDelete: null,
    onReady: null
  };

  // Default classes to use when theming
  var DEFAULT_CLASSES = {
    tokenList: "token-input-list",
    token: "token-input-token",
    tokenDelete: "token-input-delete-token",
    selectedToken: "token-input-selected-token",
    highlightedToken: "token-input-highlighted-token",
    dropdown: "token-input-dropdown",
    dropdownItem: "token-input-dropdown-item",
    dropdownItem2: "token-input-dropdown-item2",
    selectedDropdownItem: "token-input-selected-dropdown-item",
    inputToken: "token-input-input-token"
  };

  // Input box position "enum"
  var POSITION = {
    BEFORE: 0,
    AFTER: 1,
    END: 2
  };

  // Keys "enum"
  var KEY = {
    BACKSPACE: 8,
    TAB: 9,
    ENTER: 13,
    ESCAPE: 27,
    SPACE: 32,
    PAGE_UP: 33,
    PAGE_DOWN: 34,
    END: 35,
    HOME: 36,
    LEFT: 37,
    UP: 38,
    RIGHT: 39,
    DOWN: 40,
    NUMPAD_ENTER: 108,
    COMMA: 188
  };

  // Additional public (exposed) methods
  var methods = {
    init: function(url_or_data_or_function, options) {
      var settings = $.extend({}, DEFAULT_SETTINGS, options || {});

      return this.each(function () {
        $(this).data("tokenInputObject", new $.TokenList(this, url_or_data_or_function, settings));
      });
    },
    clear: function() {
      this.data("tokenInputObject").clear();
      return this;
    },
    add: function(item) {
      this.data("tokenInputObject").add(item);
      return this;
    },
    remove: function(item) {
      this.data("tokenInputObject").remove(item);
      return this;
    },
    get: function() {
      return this.data("tokenInputObject").getTokens();
    }
  }

  // Expose the .tokenInput function to jQuery as a plugin
  $.fn.tokenInput = function (method) {
    // Method calling and initialization logic
    if(methods[method]) {
      return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
    } else {
      return methods.init.apply(this, arguments);
    }
  };

  // TokenList class for each input
  $.TokenList = function (input, url_or_data, settings) {
    //
    // Initialization
    //

    // Configure the data source
    if($.type(url_or_data) === "string" || $.type(url_or_data) === "function") {
      // Set the url to query against
      settings.url = url_or_data;

      // If the URL is a function, evaluate it here to do our initalization work
      var url = computeURL();

      // Make a smart guess about cross-domain if it wasn't explicitly specified
      if(settings.crossDomain === undefined) {
        if(url.indexOf("://") === -1) {
          settings.crossDomain = false;
        } else {
          settings.crossDomain = (location.href.split(/\/+/g)[1] !== url.split(/\/+/g)[1]);
        }
      }
    } else if(typeof(url_or_data) === "object") {
      // Set the local data to search through
      settings.local_data = url_or_data;
    }

    // Build class names
    if(settings.classes) {
      // Use custom class names
      settings.classes = $.extend({}, DEFAULT_CLASSES, settings.classes);
    } else if(settings.theme) {
      // Use theme-suffixed default class names
      settings.classes = {};
      $.each(DEFAULT_CLASSES, function(key, value) {
        settings.classes[key] = value + "-" + settings.theme;
      });
    } else {
      settings.classes = DEFAULT_CLASSES;
    }


    // Save the tokens
    var saved_tokens = [];

    // Keep track of the number of tokens in the list
    var token_count = 0;

    // Basic cache to save on db hits
    var cache = new $.TokenList.Cache();

    // Keep track of the timeout, old vals
    var timeout;
    var input_val;

    // Create a new text input an attach keyup events
    var input_box = $("<input type=\"text\"  autocomplete=\"off\">")
    .css({
      outline: "none"
    })
    .attr("id", settings.idPrefix + input.id)
    .focus(function () {
      if (settings.tokenLimit === null || settings.tokenLimit !== token_count) {
        show_dropdown_hint();
      }
    })
    .blur(function () {
      hide_dropdown();
      $(this).val("");
    })
    .bind("keyup keydown blur update", resize_input)
    .keydown(function (event) {
      var previous_token;
      var next_token;

      switch(event.keyCode) {
        case KEY.LEFT:
        case KEY.RIGHT:
        case KEY.UP:
        case KEY.DOWN:
          if(!$(this).val()) {
            previous_token = input_token.prev();
            next_token = input_token.next();

            if((previous_token.length && previous_token.get(0) === selected_token) || (next_token.length && next_token.get(0) === selected_token)) {
              // Check if there is a previous/next token and it is selected
              if(event.keyCode === KEY.LEFT || event.keyCode === KEY.UP) {
                deselect_token($(selected_token), POSITION.BEFORE);
              } else {
                deselect_token($(selected_token), POSITION.AFTER);
              }
            } else if((event.keyCode === KEY.LEFT || event.keyCode === KEY.UP) && previous_token.length) {
              // We are moving left, select the previous token if it exists
              select_token($(previous_token.get(0)));
            } else if((event.keyCode === KEY.RIGHT || event.keyCode === KEY.DOWN) && next_token.length) {
              // We are moving right, select the next token if it exists
              select_token($(next_token.get(0)));
            }
          } else {
            var dropdown_item = null;

            if(event.keyCode === KEY.DOWN || event.keyCode === KEY.RIGHT) {
              dropdown_item = $(selected_dropdown_item).next();
            } else {
              dropdown_item = $(selected_dropdown_item).prev();
            }

            if(dropdown_item.length) {
              select_dropdown_item(dropdown_item);
            }
            return false;
          }
          break;

        case KEY.BACKSPACE:
          previous_token = input_token.prev();

          if(!$(this).val().length) {
            if(selected_token) {
              delete_token($(selected_token));
              hidden_input.change();
            } else if(previous_token.length) {
              select_token($(previous_token.get(0)));
            }

            return false;
          } else if($(this).val().length === 1) {
            hide_dropdown();
          } else {
            // set a timeout just long enough to let this function finish.
            setTimeout(function(){
              do_search();
            }, 5);
          }
          break;

        case KEY.TAB:
        case KEY.ENTER:
        case KEY.NUMPAD_ENTER:
        case KEY.COMMA:
          if(selected_dropdown_item) {
            add_token($(selected_dropdown_item).data("tokeninput"));
            hidden_input.change();
            return false;
          }
          break;

        case KEY.ESCAPE:
          hide_dropdown();
          return true;

        default:
          if(String.fromCharCode(event.which)) {
            // set a timeout just long enough to let this function finish.
            setTimeout(function(){
              do_search();
            }, 5);
          }
          break;
      }
    });

    // Keep a reference to the original input box
    var hidden_input = $(input)
    .hide()
    .val("")
    .focus(function () {
      input_box.focus();
    })
    .blur(function () {
      input_box.blur();
    });

    // Keep a reference to the selected token and dropdown item
    var selected_token = null;
    var selected_token_index = 0;
    var selected_dropdown_item = null;

    // The list to store the token items in
    var token_list = $("<ul />")
    .addClass(settings.classes.tokenList)
    .click(function (event) {
      var li = $(event.target).closest("li");
      if(li && li.get(0) && $.data(li.get(0), "tokeninput")) {
        toggle_select_token(li);
      } else {
        // Deselect selected token
        if(selected_token) {
          deselect_token($(selected_token), POSITION.END);
        }

        // Focus input box
        input_box.focus();
      }
    })
    .mouseover(function (event) {
      var li = $(event.target).closest("li");
      if(li && selected_token !== this) {
        li.addClass(settings.classes.highlightedToken);
      }
    })
    .mouseout(function (event) {
      var li = $(event.target).closest("li");
      if(li && selected_token !== this) {
        li.removeClass(settings.classes.highlightedToken);
      }
    })
    .insertBefore(hidden_input);

    // The token holding the input box
    var input_token = $("<li />")
    .addClass(settings.classes.inputToken)
    .appendTo(token_list)
    .append(input_box);

    // The list to store the dropdown items in
    var dropdown = $("<div>")
    .addClass(settings.classes.dropdown)
    .appendTo("body")
    .hide();

    // Magic element to help us resize the text input
    var input_resizer = $("<tester/>")
    .insertAfter(input_box)
    .css({
      position: "absolute",
      top: -9999,
      left: -9999,
      width: "auto",
      fontSize: input_box.css("fontSize"),
      fontFamily: input_box.css("fontFamily"),
      fontWeight: input_box.css("fontWeight"),
      letterSpacing: input_box.css("letterSpacing"),
      whiteSpace: "nowrap"
    });

    // Pre-populate list if items exist
    hidden_input.val("");
    var li_data = settings.prePopulate || hidden_input.data("pre");
    if(settings.processPrePopulate && $.isFunction(settings.onResult)) {
      li_data = settings.onResult.call(hidden_input, li_data);
    }
    if(li_data && li_data.length) {
      $.each(li_data, function (index, value) {
        insert_token(value);
        checkTokenLimit();
      });
    }

    // Initialization is done
    if($.isFunction(settings.onReady)) {
      settings.onReady.call();
    }

    //
    // Public functions
    //

    this.clear = function() {
      token_list.children("li").each(function() {
        if ($(this).children("input").length === 0) {
          delete_token($(this));
        }
      });
    }

    this.add = function(item) {
      add_token(item);
    }

    this.remove = function(item) {
      token_list.children("li").each(function() {
        if ($(this).children("input").length === 0) {
          var currToken = $(this).data("tokeninput");
          var match = true;
          for (var prop in item) {
            if (item[prop] !== currToken[prop]) {
              match = false;
              break;
            }
          }
          if (match) {
            delete_token($(this));
          }
        }
      });
    }
    
    this.getTokens = function() {
      return saved_tokens;
    }

    //
    // Private functions
    //

    function checkTokenLimit() {
      if(settings.tokenLimit !== null && token_count >= settings.tokenLimit) {
        input_box.hide();
        hide_dropdown();
        return;
      }
    }

    function resize_input() {
      if(input_val === (input_val = input_box.val())) {
        return;
      }

      // Enter new content into resizer and resize input accordingly
      var escaped = input_val.replace(/&/g, '&amp;').replace(/\s/g,' ').replace(/</g, '&lt;').replace(/>/g, '&gt;');
      input_resizer.html(escaped);
      input_box.width(input_resizer.width() + 30);
    }

    function is_printable_character(keycode) {
      return ((keycode >= 48 && keycode <= 90) ||     // 0-1a-z
        (keycode >= 96 && keycode <= 111) ||    // numpad 0-9 + - / * .
        (keycode >= 186 && keycode <= 192) ||   // ; = , - . / ^
        (keycode >= 219 && keycode <= 222));    // ( \ ) '
    }

    // Inner function to a token to the list
    function insert_token(item) {
      var this_token = settings.tokenFormatter(item);
      this_token = $(this_token)
      .addClass(settings.classes.token)
      .insertBefore(input_token);

      // The 'delete token' button
      $("<span>" + settings.deleteText + "</span>")
      .addClass(settings.classes.tokenDelete)
      .appendTo(this_token)
      .click(function () {
        delete_token($(this).parent());
        hidden_input.change();
        return false;
      });

      // Store data on the token
      var token_data = {
        "id": item.id
        };
      token_data[settings.propertyToSearch] = item[settings.propertyToSearch];
      $.data(this_token.get(0), "tokeninput", item);

      // Save this token for duplicate checking
      saved_tokens = saved_tokens.slice(0,selected_token_index).concat([token_data]).concat(saved_tokens.slice(selected_token_index));
      selected_token_index++;

      // Update the hidden input
      update_hidden_input(saved_tokens, hidden_input);

      token_count += 1;

      // Check the token limit
      if(settings.tokenLimit !== null && token_count >= settings.tokenLimit) {
        input_box.hide();
        hide_dropdown();
      }

      return this_token;
    }

    // Add a token to the token list based on user input
    function add_token (item) {
      var callback = settings.onAdd;

      // See if the token already exists and select it if we don't want duplicates
      if(token_count > 0 && settings.preventDuplicates) {
        var found_existing_token = null;
        token_list.children().each(function () {
          var existing_token = $(this);
          var existing_data = $.data(existing_token.get(0), "tokeninput");
          if(existing_data && existing_data.id === item.id) {
            found_existing_token = existing_token;
            return false;
          }
        });

        if(found_existing_token) {
          select_token(found_existing_token);
          input_token.insertAfter(found_existing_token);
          input_box.focus();
          return;
        }
      }

      // Insert the new tokens
      if(settings.tokenLimit == null || token_count < settings.tokenLimit) {
        insert_token(item);
        checkTokenLimit();
      }

      // Clear input box
      input_box.val("");

      // Don't show the help dropdown, they've got the idea
      hide_dropdown();

      // Execute the onAdd callback if defined
      if($.isFunction(callback)) {
        callback.call(hidden_input,item);
      }
    }

    // Select a token in the token list
    function select_token (token) {
      token.addClass(settings.classes.selectedToken);
      selected_token = token.get(0);

      // Hide input box
      input_box.val("");

      // Hide dropdown if it is visible (eg if we clicked to select token)
      hide_dropdown();
    }

    // Deselect a token in the token list
    function deselect_token (token, position) {
      token.removeClass(settings.classes.selectedToken);
      selected_token = null;

      if(position === POSITION.BEFORE) {
        input_token.insertBefore(token);
        selected_token_index--;
      } else if(position === POSITION.AFTER) {
        input_token.insertAfter(token);
        selected_token_index++;
      } else {
        input_token.appendTo(token_list);
        selected_token_index = token_count;
      }

      // Show the input box and give it focus again
      input_box.focus();
    }

    // Toggle selection of a token in the token list
    function toggle_select_token(token) {
      var previous_selected_token = selected_token;

      if(selected_token) {
        deselect_token($(selected_token), POSITION.END);
      }

      if(previous_selected_token === token.get(0)) {
        deselect_token(token, POSITION.END);
      } else {
        select_token(token);
      }
    }

    // Delete a token from the token list
    function delete_token (token) {
      // Remove the id from the saved list
      var token_data = $.data(token.get(0), "tokeninput");
      var callback = settings.onDelete;

      var index = token.prevAll().length;
      if(index > selected_token_index) index--;

      // Delete the token
      token.remove();
      selected_token = null;

      // Show the input box and give it focus again
      input_box.focus();

      // Remove this token from the saved list
      saved_tokens = saved_tokens.slice(0,index).concat(saved_tokens.slice(index+1));
      if(index < selected_token_index) selected_token_index--;

      // Update the hidden input
      update_hidden_input(saved_tokens, hidden_input);

      token_count -= 1;

      if(settings.tokenLimit !== null) {
        input_box
        .show()
        .val("")
        .focus();
      }

      // Execute the onDelete callback if defined
      if($.isFunction(callback)) {
        callback.call(hidden_input,token_data);
      }
    }

    // Update the hidden input box value
    function update_hidden_input(saved_tokens, hidden_input) {
      var token_values = $.map(saved_tokens, function (el) {
        return el[settings.tokenValue];
      });
      hidden_input.val(token_values.join(settings.tokenDelimiter));

    }

    // Hide and clear the results dropdown
    function hide_dropdown () {
      dropdown.hide().empty();
      selected_dropdown_item = null;
    }

    function show_dropdown() {
      dropdown
      .css({
        position: "absolute",
        top: $(token_list).offset().top + $(token_list).outerHeight(),
        left: $(token_list).offset().left,
        zindex: 999
      })
      .show();
    }

    function show_dropdown_searching () {
      if(settings.searchingText) {
        dropdown.html("<p>"+settings.searchingText+"</p>");
        show_dropdown();
      }
    }

    function show_dropdown_hint () {
      if(settings.hintText) {
        dropdown.html("<p>"+settings.hintText+"</p>");
        show_dropdown();
      }
    }

    // Highlight the query part of the search term
    function highlight_term(value, term) {
      return value.replace(new RegExp("(?![^&;]+;)(?!<[^<>]*)(" + term + ")(?![^<>]*>)(?![^&;]+;)", "gi"), "<b>$1</b>");
    }
    
    function find_value_and_highlight_term(template, value, term) {
      return template.replace(new RegExp("(?![^&;]+;)(?!<[^<>]*)(" + value + ")(?![^<>]*>)(?![^&;]+;)", "g"), highlight_term(value, term));
    }

    // Populate the results dropdown with some results
    function populate_dropdown (query, results) {
      if(results && results.length) {
        dropdown.empty();
        var dropdown_ul = $("<ul>")
        .appendTo(dropdown)
        .mouseover(function (event) {
          select_dropdown_item($(event.target).closest("li"));
        })
        .mousedown(function (event) {
          add_token($(event.target).closest("li").data("tokeninput"));
          hidden_input.change();
          return false;
        })
        .hide();

        $.each(results, function(index, value) {
          var this_li = settings.resultsFormatter(value);
                
          this_li = find_value_and_highlight_term(this_li ,value[settings.propertyToSearch], query);            
                
          this_li = $(this_li).appendTo(dropdown_ul);
                
          if(index % 2) {
            this_li.addClass(settings.classes.dropdownItem);
          } else {
            this_li.addClass(settings.classes.dropdownItem2);
          }

          if(index === 0) {
            select_dropdown_item(this_li);
          }

          $.data(this_li.get(0), "tokeninput", value);
        });

        show_dropdown();

        if(settings.animateDropdown) {
          dropdown_ul.slideDown("fast");
        } else {
          dropdown_ul.show();
        }
      } else {
        if(settings.noResultsText) {
          dropdown.html("<p>"+settings.noResultsText+"</p>");
          show_dropdown();
        }
      }
    }

    // Highlight an item in the results dropdown
    function select_dropdown_item (item) {
      if(item) {
        if(selected_dropdown_item) {
          deselect_dropdown_item($(selected_dropdown_item));
        }

        item.addClass(settings.classes.selectedDropdownItem);
        selected_dropdown_item = item.get(0);
      }
    }

    // Remove highlighting from an item in the results dropdown
    function deselect_dropdown_item (item) {
      item.removeClass(settings.classes.selectedDropdownItem);
      selected_dropdown_item = null;
    }

    // Do a search and show the "searching" dropdown if the input is longer
    // than settings.minChars
    function do_search() {
      var query = input_box.val().toLowerCase();

      if(query && query.length) {
        if(selected_token) {
          deselect_token($(selected_token), POSITION.AFTER);
        }

        if(query.length >= settings.minChars) {
          show_dropdown_searching();
          clearTimeout(timeout);

          timeout = setTimeout(function(){
            run_search(query);
          }, settings.searchDelay);
        } else {
          hide_dropdown();
        }
      }
    }

    // Do the actual search
    function run_search(query) {
      var cache_key = query + computeURL();
      var cached_results = cache.get(cache_key);
      if(cached_results) {
        populate_dropdown(query, cached_results);
      } else {
        // Are we doing an ajax search or local data search?
        if(settings.url) {
          var url = computeURL();
          // Extract exisiting get params
          var ajax_params = {};
          ajax_params.data = {};
          if(url.indexOf("?") > -1) {
            var parts = url.split("?");
            ajax_params.url = parts[0];

            var param_array = parts[1].split("&");
            $.each(param_array, function (index, value) {
              var kv = value.split("=");
              ajax_params.data[kv[0]] = kv[1];
            });
          } else {
            ajax_params.url = url;
          }

          // Prepare the request
          ajax_params.data[settings.queryParam] = query;
          ajax_params.type = settings.method;
          ajax_params.dataType = settings.contentType;
          if(settings.crossDomain) {
            ajax_params.dataType = "jsonp";
          }

          // Attach the success callback
          ajax_params.success = function(results) {
            if($.isFunction(settings.onResult)) {
              results = settings.onResult.call(hidden_input, results);
            }
            cache.add(cache_key, settings.jsonContainer ? results[settings.jsonContainer] : results);

            // only populate the dropdown if the results are associated with the active search query
            if(input_box.val().toLowerCase() === query) {
              populate_dropdown(query, settings.jsonContainer ? results[settings.jsonContainer] : results);
            }
          };

          // Make the request
          $.ajax(ajax_params);
        } else if(settings.local_data) {
          // Do the search through local data
          var results = $.grep(settings.local_data, function (row) {
            return row[settings.propertyToSearch].toLowerCase().indexOf(query.toLowerCase()) > -1;
          });

          if($.isFunction(settings.onResult)) {
            results = settings.onResult.call(hidden_input, results);
          }
          cache.add(cache_key, results);
          populate_dropdown(query, results);
        }
      }
    }

    // compute the dynamic URL
    function computeURL() {
      var url = settings.url;
      if(typeof settings.url == 'function') {
        url = settings.url.call();
      }
      return url;
    }
  };

  // Really basic cache for the results
  $.TokenList.Cache = function (options) {
    var settings = $.extend({
      max_size: 500
    }, options);

    var data = {};
    var size = 0;

    var flush = function () {
      data = {};
      size = 0;
    };

    this.add = function (query, results) {
      if(size > settings.max_size) {
        flush();
      }

      if(!data[query]) {
        size += 1;
      }

      data[query] = results;
    };

    this.get = function (query) {
      return data[query];
    };
  };
}(jQuery));
